Prediction of the Pressure Drop Through Micromachined Particle Filters

Micro-filters are fabricated using MEMS technology, and both measurements and numerical calculations are carried out in order to estimate the power requirement in a micron-size particle collection process using the microfilter. In order to numerically predict the pressure drop through the micro-filter, we focus on the characterization of the geometrical factors, such as internal profile of the filtering hole and the hole dimension. The surface slip is also considered. It is found that the pressure drop through the micro-filter is strongly dependent upon the internal profile of the filtering hole and that the surface-slip is not dominant in determining the pressure drop. When the size of the hole is accurately measured and the internal profile of the filtering hole is correctly modeled, the calculated pressure drop shows good agreement with the measured pressure drop. From the numerical calculation, a formula is proposed which can accurately predict the pressure drop through the micro-filter.